Motor graders are used primarily as a finishing tool to sculpt a surface of earth to a final arrangement. To perform such earth sculpting tasks, motor graders include a blade, also referred to as a moldboard or implement. The blade moves relatively small quantities of earth from side to side. Motor graders must produce a variety of final earth arrangements. As a result, the blade must be set to many different blade positions.
The blade may be adjusted for blade height, blade cutting angle, blade tip, blade sideshift, and drawbar sideshift. Accordingly, motor graders include several hand controls to operate the multiple blade adjustments. Positioning the blade of a motor grader is a complex and time consuming task. Frequently, a motor grader will spread material to one direction perpendicular to the path of travel. In other words, the motor grader will spread material across the area being graded, not straight ahead. Typically, this is accomplished by making a first pass over the material with the blade at a first blade position. The first blade position may be defined by the blade cutting angle, the blade sideshift, and/or the drawbar sideshift. At the end of the pass, the motor grader will need to turn around and make a second pass over the material. To spread the material in the same direction, the blade should be repositioned to a mirror image of the first pass. In other words, the blade position for the second pass should be a mirror image of the first blade position to continue to spread the material in the same direction. Thus, to increase efficiency, it is desirable to provide a method for controlling the blade controls to automatically produce a mirror image of the current blade position.